Solve last struct and generics

exercises/generics/generics1.rs

@@ -1,10 +1,8 @@
 // This shopping list program isn't compiling! 
 // Use your knowledge of generics to fix it.
 
-// I AM NOT DONE
-
 fn main() {
-    let mut shopping_list: Vec<?> = Vec::new();
+    let mut shopping_list: Vec<&str> = Vec::new();
     shopping_list.push("milk");
 }
 

exercises/generics/generics2.rs

@@ -1,13 +1,12 @@
 // This powerful wrapper provides the ability to store a positive integer value.
 // Rewrite it using generics so that it supports wrapping ANY type.
 
-// I AM NOT DONE
-struct Wrapper {
-    value: u32
-}
+struct Wrapper<T> {
+    value: T
+} 
 
-impl Wrapper {
-    pub fn new(value: u32) -> Self {
+impl<T> Wrapper<T> {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }

exercises/generics/generics3.rs

@@ -7,17 +7,16 @@
 // Make the necessary code changes to support alphabetical report cards, thereby making 
 // the second test pass.
 
-// I AM NOT DONE
-pub struct ReportCard {
-    pub grade: f32,
+pub struct ReportCard<T> {
+    pub grade: T,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl<T: ToString> ReportCard<T> {
     pub fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}", 
-            &self.student_name, &self.student_age, &self.grade)
+            &self.student_name, &self.student_age, &self.grade.to_string())
     }
 }
 
@@ -37,9 +36,8 @@ mod tests {
 
     #[test]
     fn generate_alphabetic_report_card() {
-        // TODO: Make sure to change the grade here after you finish the exercise.
         let report_card = ReportCard {
-            grade: 2.1, 
+            grade: "A+", 
             student_name: "Gary Plotter".to_string(), 
             student_age: 11,
         };

exercises/structs/structs3.rs

@@ -22,12 +22,12 @@ impl Package {
 
     fn is_international(&self) -> bool {
         // Something goes here...
-        self.from != self.to
+        self.recipient_country != self.sender_country
     }
 
     fn get_fees(&self, cents_per_kg: i32) -> i32 {
         // Something goes here... (beware of grams to kg conversion)
-        self.weight * cost_per_kg
+        (self.weight_in_grams * cents_per_kg) / 100
     }
 }
 
@@ -59,7 +59,7 @@ mod tests {
         let sender_country = String::from("Spain");
         let recipient_country = String::from("Spain");
 
-        let cents_per_kg = 8.0;
+        let cents_per_kg = 300;
         
         let package = Package::new(sender_country, recipient_country, 1500);